Method and apparatus tor manufacturing incandescent-lamp bulbs



R. LE R-OSSIGNOL.

ninlon AND APPARATUS FOR mnuncrunms mcmossczm um BULBS.

APPLICATION HLFD JAN. 30. I9".

Patented Sept. 9, 1919.

Inventor- Robert LeRossi no!,

big His Attomeg.

UNITED STATES PATENT OFFICE.

ROBERT LE ROS'SIGNOL, 0F BERLIN, GERMANY, ASSIG-NOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

METHOD AN D APPARATUS FOR MANUFACTURING INCANDESGENT-LAMP BULBS.

Specification of Letters Patent.

Patented Sept. 9, 1919.

Application filed January 30, 1917. Serial No. 145,564.

To all whom it may concern:

Be it known that I, Ronnn'r Ln R/OSSIGNOL, a subject of the King of Great Britain, residing at Berlin, Germany, have invented cer tain new and useful Improvements in Methods and Apparatus for Manufacturing Incandescent-Lamp Bulbs, of Which the following is a specification.

My invention relates to an improved incandescent electric lamp, as Well as to a method and an apparatus for manufacturing the improved lamp.

It has heretofore been customary in manufacturing incandescent electric lamps to make an opening in the bulb, then seal or weld an exhaust tube to the bulb to communicate with the opening, then seal in the flare or mount which carries the filament, then exhaust the lamp through the exhaust tube, and finally seal off the lamp from the pump and hermetically close it by melting down the exhaust tube. The object of my invention is to bring about a considerable reduction in the number of steps or operations heretofore necessary to accomplish the desired result. Another object is to make a substantial saving in glass.

In accordance with my invention the incandescent lamp is not provided with an extra tube sealed or welded on in the customary manner, but instead has only a short tubulature which is formed from the material of the wall of the lamp itself. The lamp is exhausted through this tubulature, which is of such small dimensions that it need not be removed after the lamp is exhausted. By my invention the special exhaust tubes, which become useless afthr having been used once or twice, are rendered unnecessary.

Lamps constructed in accordance with my invention are particularly well adapted to be exhausted very quickly and easily by a process in which the lamps during exhaustion are suitably disposed in a receptacle which may be exhausted at will and with which the lamps communicate through their tubulatures, which are hermetically sealed after the desired vacuum is obtained and while the lamps are still in the receptacle.

In accordance with my invention the improved lamp may be manufactured as follows: At the point at which the tubulature is to be formed the lamp wall is heated until it is plastic, and then the tubulature is formed from the plastic wall of the lamp by means of a suitably shaped plug-core or mandrel, which is thrust into the plastic Wall of the lamp, deforming it and extending the material into a short tubulature communicating with the interior of the lamp and having the shape and size of the mandrel. This method permits the tubulature to be formed rapidly and easily at any suitable point in the well of the lamp. The stem or flare is particularly Well adapted for the formation of the tubulature in this way, since it has a thicker wall than the bulb and thus always provides at a suitable point sufiicient material for forming the tubulature. In accordance with my invention tipless incandescent lamps may very easily be made.

My invention will best be understood in connection with the accompanyin drawing in which merely for purposes of il ustration, I have shown one form of an improved incandescent lamp embodying my invention as well as one form of apparatus suitable for carrying out my novel method. In the drawing Figure 1 represents an incandescent lamp embodying my invention and having a tubulature made in accordance with my novel method. Fig. 2 is a bottom plan view of an apparatus useful in forming the tubulature in the flare or stem, and Fig. 3 is a side view of the device shown in Fig. 2.

In the particular form of lamp shown in the drawing, the tubulature (a) is made in the side of the tubular flare or stem (5) and is integral with it. This tubulature is made in accordance with my invention by deforming and molding a plastic portion of the wall of the flare into a tubulature substantially as illustrated in Fig. 1.

When the tubulature is to be formed in the side of the flare, the flare may be mounted in a rotatable holder or chuck (c), where it is heated by a blow-pipe flame (d) while the chuck rotates. After the flare has in this manner been subjected to a general heating in the region where the tubulature is to be formed, the blow-pipe flame is withdrawn, the chuck (c) is stopped, and a pointed flame (e) is directed upon the flare at the particular point or local region at which the tubulature is to be formed. When this local heating has progressed until the particular spot is sufli-ciently soft and plastic, a lever (f), pivoted adjacent the chuck (c), and carrying on its free end a plug-core or mandrel (g) considerably less in diameter than the heated spot, is swung, as best shown in Fig.

2, from its normal position shown in full lin es into the rposition shown in dotted lines. In its Il'lOVGIIlBIll; the tip of the mandrel (g) first strikes the heated wall or plastic portion of the Hare (b) and then as the mandrel continues to move toward the dotted line position, the plastic glass is deformed and molded, and stretched to some extent if necessary, to form the 'tubulature (as) out of the wall ofthe flare (ii), the tubulature (a) with its walls 'thickenough to permit sealing of the lamp. As'sh'own in Fig. 3 the lever (f) ishowed or bent to one side at the middle so that the only object which strikes the heated wall of the lime is the mandrel (g). The tnhulature (a) is integral with the flare (7)) and is molded or formed from the plastic material of the walls of the flare. After the tubulaturehas been formed, itsti'p can be broken off in any desired way to open it, or the tubnlature can be otherwise opened.

hat I claim as new and desireto secure by Letters Patent of the United States, is,- 1. In a device of the character described the combination of arotatable holder "for glassware, a bni'ner'ad-iacent said holder for heating the were, a second lollr'ner adjacent sa'id holder for locally heating a spot upon said were. when said holder is stationary, and a cylindrical mandrel-mounted adjaeent said holderto move end'wise toward said holder to en age anddeform the locally heated spot on the Write into a tubular projection having walls thiekenough to 'be hermetically sealed. 2. In a device of the character described the combination of a rotatable chuck for holding the glassware, a burner for locally heating a spot on the glassware until it is plastic, a "mandrel mounted adjacent said chuck and pivoted to swing onan are which passesthroughthefiame of said burner, and

means for swinging said mandrel about its pivot toward the ware in said holder and thereby thrusting said mandrel into the locally heated spot on the wars and thereby deforming the glass of the ware at said spot into a tubular extension with Walls thick enough to permit hermetical sealing.

The method which comprises locally heating a spot on the wall of glassware until it becomes plastic and molding from the heated material at said spot a tubular extension. with walls thick enough to permit hermetical sealing of the extension and merging 'wi thout joint-s into the walls of the glassware.

4-. The method which comprises locally heating a spot on the wall of glassware until the glass at said spot is plastic and thrusting into the wall of the glassware at said heated spot ae lindrical mandrel of a diameter less than that of the heated spot to shape the plastic glass at said spot into a tubular projection with Walls thick enough to permit hermetical sealing and merging without joints into the wall of the glass.

5. The method producing in the wall of tubular glassware a tubular projection extending toward the interior of the ware which 'COll'lIJ'I'lSGS locally heating a restricted area-on the wall of the were until it is plastic and thrusting a cylindrical -n1andrel hav- ROBERT LE ROSSIGNOL.

Witnesses:

HENRY Hesrnn, ALLEN F. JENNINGS.

floplel'althis patent may be obtained larflve cents each, by addressing the Commissioner of Latents, Washington, D. G. 

